SPOILER!!!!
A deity named Mado asked the first king a question
"If you can save 99 for the sacrifice of killing 1 person.. will you do it?"
the king answered yes "I will do it but I will bear the sin of sacrificing 1 for the many."
then mado replied "You deserve to be the King."
he granted the first king immense power through a sentence (kinda like a spell)
but what he dodn't know was that in return he had to sacrifice the person he loved the most. His companion.
Im finally starting to understand all the missing pieces trough everyone spoilers but what do you mean Nina was the kings companion before? Does it mean that before the timeline where the king fell in love with the Saintess he love Nina before, with different body? Or he treats her just a companion with no love? Cuz if I understand it correctly then this was Nina character 3rd time (with different souls). Thanks!
SPOILERRR
Spoiler and Clarifictions to finally clear things up.
1. Nina is the Pope's sister. The pope is in love with cerapei and it was him who convinced the king to kill Nina for Cerapei's safety
2. Nina is probably the reincarnation of the First King's companion. (This is a theory made by the korean readers because it bothe the original story and in hayoon's time as nina the King feels something everytime they interact
3. Beatto is not a main lead but some one who holds Nina dearly out of worry
4. Nina and Cerapei are friends periodt
5. The real romance starts 5 years later.
6. Again i am reminding everyone that Hayoon lee who is currently inside Nina is probably older than 20 because she was an office worker in the modern world and it doesn't look like she's a new grad.